Is it possible to override a cornerstone element template, and ideally also expand upon it’s existing functionality? For example, if I would like to add some additional options for displaying recent posts and how they are formatted in the template, is there a clean way to update/override the templates and extend the existing element, or do I need to just create my own completely separate element?
Overriding existing functionality of current elements is possible but it would be outside the scope of our support. We can help you with adjusting design through simple CSS but other than that, in case you are not comfortable editing codes, you may wish to consult a developer to achieve this. This guide might help: https://theme.co/apex/forum/t/cornerstone-custom-elements/217